Users can also tweet links directly from the Android web market. You can't do that in iTunes.

You can buy an app on the web and it downloads to your phone. That's something you can't do on the iPhone/iPad.

This is a very good, important development for Google, the Android platform, and Android developers. The Web app store makes it much easier to discover apps. (Consider: Now we'll be able to link to Android apps when we write about them. So will everyone else.)